<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width= , initial-scale=1.0">
    <title>学成在线教育平台-不是每个网站都叫学成在线</title>
    <link rel="stylesheet" href="CSS/base.css">
    <link rel="stylesheet" href="CSS/index.css">
    <link rel="shortcut icon" href="favicon.ico" />
    <style>
         div{
            height: 30px;
            width:300px;
            border: 1px solid red;
            line-height: 30px;
        }
        span{
            display: inline-block;
            vertical-align: middle;  /*一起使用  文字不会随着块一起移动*/
            width: 8px;
            height: 8px;
            background-color: green; 
            margin-top: -1px;
        } 

    </style>
</head>
<body>
    <div>
        <span></span>文字
    </div>
    <header>
        
    </header>
</body>
</html>